An Etymological Dictionary of Astronomy and Astrophysics

The angular velocity of a point in a circular orbit around a central mass. It is given by:
Ω_K = (GM/r³)^1/2,
where G is the → gravitational constant, M is the mass of the gravitating object, and r is the radius of the orbit of the point around the object.

See also: → Keplerian; → angular; → velocity.